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Thoracic and Breathing Evaluation in Shoulder Clinical Reasoning

Original Editor - Ewa Jaraczewska based on the course by Ari Kaplan

Top Contributors - Ewa Jaraczewska and Jess Bell  

Introduction

The shoulder does not work in isolation. The thoracic spine and rib cage provide the base on which the scapula and glenohumeral joint operate. Thoracic stiffness, restricted rib mobility, and dysfunctional breathing patterns can all contribute to shoulder issues, such as impingement, rotator cuff overload, and reduced overhead mobility. These contributing factors are often underappreciated in clinical practice but can respond well to targeted intervention. This page explores how the thoracic spine and breathing patterns affect shoulder mobility. Self-assessment exercises are included throughout to help you experience these mechanics first-hand and apply them in clinical practice.

Relationship Between the Thoracic Spine and the Shoulder

Reaching overhead requires approximately 10–13° of thoracic extension, distributed across the upper, mid, and lower thoracic segments.[1] Insufficient thoracic extension causes compensation at the shoulder complex, which places increased demand on the glenohumeral joint.[2][3] Conversely, adequate thoracic extension enables the scapulothoracic stabilisers (serratus anterior and lower trapezius) to function effectively.[2]

Most of this extension occurs in the mid-thoracic spine, with the upper and lower segments contributing smaller amounts.[4] Extension in the upper thoracic spine, though smaller in magnitude, is particularly important for shoulder function, as it facilitates upward rotation and posterior tilt of the scapula.[5]

The degree of resting kyphosis directly predicts available thoracic extension.[6] In other words, a patient who habitually sits or stands in a kyphotic posture has less extension available for overhead movement.[7]

Mid-Thoracic Kyphosis

Increased kyphosis in the mid-thoracic spine restricts extension. This can result in a significant loss of overhead range of motion.[5] Achieving full range of motion with increased mid-thoracic kyphosis requires compensation, typically through overuse of the glenohumeral joint, which predisposes a person to impingement and rotator cuff overload.

Try this for yourself: Reach both arms fully overhead. Notice the natural extension through your mid-back. Now slump into a kyphotic position and repeat. Feel the restriction?

Upper Thoracic Kyphosis and Forward Head Posture

A forward head posture biases the scapula toward elevation rather than upward rotation.[7] The upper trapezius and levator scapulae become dominant, hiking the scapula rather than allowing it to rotate. This disrupts the normal scapulohumeral rhythm and places additional stress on the glenohumeral joint.[8]

Try this for yourself: Poke your head forward and reach both arms overhead. Notice how the movement feels effortful? Do your shoulders shrug upward rather than your arms arcing smoothly overhead?

The Relationship Between Rib Mobility and the Shoulder

The scapula sits directly on the posterior rib cage. This means that rib mobility plays an important role in scapular kinematics. If the ribs cannot expand and rotate outward, the scapula cannot move efficiently across them.[9]

Restricted rib mobility, particularly when combined with thoracic kyphosis, can displace the scapula laterally, altering the length-tension relationship of surrounding musculature and the orientation of the glenoid.[10] For overhead elevation to occur without impingement, the scapula must upwardly rotate, posteriorly tilt, and externally rotate; all three motions depend on a mobile rib cage.

The Relationship Between Breathing Patterns and the Shoulder

Breathing is one of the most clinically significant factors influencing rib and thoracic mobility.[4] Respiration involves the coordinated movement of the sternum, ribs, thoracic vertebrae, intervertebral discs, joints, muscles, and ligaments. The ribs connect to the thoracic vertebrae at the costovertebral and costotransverse joints. The true ribs also join the sternum at the sternocostal joints. Together, these structures allow the thoracic cavity to expand during breathing. The diaphragm is the primary driver of this expansion, supported by the external intercostal muscles and, during more effortful breathing, the scalene muscles.[11]

Normal Diaphragmatic Breathing

The diaphragm descends during inhalation.[12] This drives the lower ribs to expand laterally and posteriorly and generates negative intrathoracic pressure, drawing air into the lungs.[11] A healthy person takes approximately 20,000 breaths per day.[13] With each breath, the rib joints move through their range of motion. This regular movement helps maintain costovertebral joint mobility — without it, stiffness can develop over time.

Dysfunctional Breathing Patterns

When accessory muscles dominate breathing, the consequences extend to scapular and shoulder mechanics.

Costovertebral stiffness: During quiet breathing, the costotransverse joints move through small, multi-planar movements, typically around 1 mm.[14] If the ribs stop cycling through their full range of motion because of dysfunctional breathing patterns, the joints gradually stiffen.[4]

Elevated first and second rib: Accessory breathing patterns can, over time, increase scalene activity, chronically elevating the upper ribs. This alters the resting position of the scapula and limits upward rotation.[15]

Scapular malposition: An elevated ribcage displaces the scapula from its optimal resting position. This alters shoulder mechanics even before the arm begins to move, requiring greater effort during movement, limiting range of motion, and increasing the risk of impingement or pain.[16]

Cervical contribution: It has been reported that shoulder pain occurs in 50% of patients with cervical dysfunction.[17] This may result from direct cervical referral or from the mechanical effects of chronic cervical dysfunction, which can lead to overactive scalenes and sternocleidomastoids, further elevating the ribs and compounding scapular dysfunction.[4][18][19]

This optional video demonstrates breathing exercises to improve shoulder motion:

[20]

Observational Assessment

A structured observation can help guide your clinical reasoning. The following sequence is conducted in sitting.[4]

Active shoulder flexion: Watch for thoracic extension in the final third of shoulder flexion range. Its absence may suggest either a motor control or a mobility issue, but observation alone cannot distinguish between the two.

Isolated thoracic extension test: Ask the patient to cross their arms and actively extend their thoracic spine. Minimal or absent motion, or substitution through the thoracolumbar junction, increases suspicion of a mobility restriction.

Palpation of the thoracic erector spinae: Elevated tone in the region where extension should be occurring, particularly if it is unilateral, supports the likelihood of a mobility impairment.

Breathing observation: Ask the patient to take a deep breath and watch for lateral rib expansion versus shoulder elevation. Shoulder elevation rather than lateral rib expansion suggests an accessory breathing pattern. An anterior rib flare combined with extension through the thoracolumbar junction may suggest a more ingrained dysfunctional breathing pattern that may require more focused intervention.

Summary

Thoracic extension of approximately 10–13° is required for normal overhead movement. Both mid-thoracic and upper thoracic kyphosis alter scapular mechanics, but through different mechanisms. Rib mobility is essential for optimal scapular movement, but dysfunctional breathing patterns can drive rib and thoracic stiffness over time. Observing a patient’s breathing pattern is an important component of the overall shoulder assessment. When thoracic, rib, and breathing impairments are identified and addressed, overhead movement and shoulder symptoms can often improve.

Resources

References

  1. ↑ Edmondston S, Ferguson A, Ippersiel P, Ronningen L, Sodeland S, Barclay L. Clinical and radiological investigation of thoracic spine extension motion during bilateral arm elevation. journal of orthopaedic & sports physical therapy. 2012 Oct;42(10):861-9.
  2. ↑ 2.0 2.1 Howe L, Read P. Thoracic spine function: assessment and self management. Professional Journal of Strength and Conditioning. 2015;39:21-31.
  3. ↑ Tate AR, McClure PW, Young IA, Salvatori R, Michener LA. Comprehensive impairment-based exercise and manual therapy intervention for patients with subacromial impingement syndrome: a case series. J Orthop Sports Phys Ther. 2010 Aug;40(8):474-93.
  4. ↑ 4.0 4.1 4.2 4.3 4.4 Kaplan A. Thoracic and Breathing Evaluation in Shoulder Clinical Reasoning Course. Physiopedia Plus, 2026.
  5. ↑ 5.0 5.1 Yoshimi M, Maeda N, Komiya M, Fukui K, Tashiro T, Kaneda K, Arima S, Tsutsumi S, Abekura T, Urabe Y. Effect of thoracic expansion restriction on scapulothoracic and glenohumeral joint motion during shoulder external rotation. J Back Musculoskelet Rehabil. 2022;35(6):1399-1406.
  6. ↑ Park KH, Oh JS, An DH, Yoo WG, Kim JM, Kim TH, Kang MH. Difference in selective muscle activity of thoracic erector spinae during prone trunk extension exercise in subjects with slouched thoracic posture. PM&R. 2015 May 1;7(5):479-84.
  7. ↑ 7.0 7.1 Hunter DJ, Rivett DA, McKeirnan S, Smith L, Snodgrass SJ. Relationship between shoulder impingement syndrome and thoracic posture. Physical therapy. 2020 Apr;100(4):677-86.
  8. ↑ Kwon JW, Son SM, Lee NK. Changes in upper-extremity muscle activities due to head position in subjects with a forward head posture and rounded shoulders. J Phys Ther Sci. 2015 Jun;27(6):1739-42.
  9. ↑ Gray J, Grimsby O. Interrelationship of the spine, rib cage, and shoulder. Physical Therapy of the Shoulder, R. Donatelli, Ed. 2011 Mar 16:87-130.
  10. ↑ Strunce JB, Walker MJ, Boyles RE, Young BA. The immediate effects of thoracic spine and rib manipulation on subjects with primary complaints of shoulder pain. J Man Manip Ther. 2009;17(4):230-6.
  11. ↑ 11.0 11.1 Ristovski A, Kapeleti M, Zlatović I, Mrdaković V. Acute Effects of Diaphragmatic Breathing on Trunk and Shoulder Mobility and Pulmonary Function in Healthy Young Adults. Journal of Functional Morphology and Kinesiology. 2025 Aug 23;10(3):325.
  12. ↑ Rivas Ebner MC, Ackah E, Kim SW, Seok YS, Choi SH. Kinematic Monitoring of the Thorax During the Respiratory Cycle Using a Biopolymer-Based Strain Sensor: A Chitosan–Glycerol–Graphite Composite. Biosensors. 2025 Aug 9;15(8):523.
  13. ↑ Ristovski A, Mrdaković V. The importance of breathing exercises for fitness and health. Proceedings Book. 2023;195.
  14. ↑ Maninang M, Almeter G, Pearson E, Vitente A. Biomechanics of the ribs during respiration at the costotransverse joint: an in-vivo retrospective pilot study. Philippine Journal of Physical Therapy. 2025;4(3):23-8.
  15. ↑ Mastromarchi P, May S. First rib dysfunction in patients with neck and shoulder pain: a Delphi investigation. J Man Manip Ther. 2021 Jun;29(3):181-188.
  16. ↑ Paine R, Voight ML. The role of the scapula. Int J Sports Phys Ther. 2013 Oct;8(5):617-29.
  17. ↑ Roldán-Ruiz A, Bailón-Cerezo J, Falla D, Torres-Lacomba M. The prevalence of cervical contribution in patients reporting shoulder pain. An observational study. Musculoskelet Sci Pract. 2024 Oct;73:103158.
  18. ↑ Roldán-Ruiz A, Bailón-Cerezo J, Bertotti G, Torres-Lacomba M. Cervical contribution in musculoskeletal shoulder pain. A review of the literature. Journal of Bodywork and Movement Therapies. 2025 Jun 1;42:360-7.
  19. ↑ Pheasant S. CERVICAL CONTRIBUTION TO FUNCTIONAL SHOULDER IMPINGEMENT: TWO CASE REPORTS. Int J Sports Phys Ther. 2016 Dec;11(6):980-991.
  20. ↑ Markow Training Systems. Breathing for Improved Shoulder Flexion (from the Personal Trainer Academy). Available from: https://www.youtube.com/watch?8MA2JnSWzP8 [last accessed 24/02/2026]
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